Cardiology Coding Alert

Question: The cardiologist performed selective coronary angiogram and a left cardiac catheterization with left ventriculogram on a patient with chest pain whose ECG showed acute myocardial infarction. He found complete obstruction of the LAD and completed a successful stent placement. Final diagnosis was acute posterolateral myocardial infarction and single vessel CAD. The patient’s past medical history includes hypertension, GERD, and history of MI. Which codes should I report?

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Answer: For the stent placement on a patient during acute myocardial infarction (AMI), you should report 92941-LD (Percutaneous transluminal revascularization of acute total/subtotal occlusion during acute myocardial infarction, coronary artery or coronary artery bypass graft, any combination of intracoronary stent, atherectomy and angioplasty, including aspiration thrombectomy when performed, single vessel; Left anterior descending coronary artery).

Assuming documentation supports the heart cath and angiography as truly diagnostic, you should report those services with 93458-26-59 (Catheter placement in coronary artery[s] for coronary angiography, including intraprocedural injection[s] for coronary angiography, imaging supervision and interpretation; with left heart catheterization including intraprocedural injection[s] for left ventriculography, when performed; Professional component; Distinct procedural service).

Your first-listed diagnosis should be the AMI, using 410.51 (Acute myocardial infarction of other lateral wall initial episode of care). The mapped ICD-10 code is I21.29 (ST elevation [STEMI] myocardial infarction involving other sites).

You should add 414.01 (Coronary atherosclerosis of native coronary artery) for the coronary artery disease (CAD). Under ICD-10, one possible cross is I25.119 (Atherosclerotic heart disease of native coronary artery with unspecified angina pectoris).

When deciding whether to include codes for the past medical history diagnoses, remember that ICD-9 guidelines state, “Code all documented conditions that coexist at the time of the encounter/visit, and require or affect patient care treatment or management. Do not code conditions that were previously treated and no longer exist. However, history codes (V10-V19) may be used as secondary codes if the historical condition or family history has an impact on current care or influences treatment.”

So if the physician mentions taking the other diagnoses into account (e.g., in medications prescribed or in deciding how to proceed), it would be appropriate to report those, too:

• Hx MI: 412, Old myocardial infarction (ICD-10: I25.2, Old myocardial infarction)
• Hypertension: 401.9, Unspecified essential hypertension (ICD-10: I10, Essential [primary] hypertension)
• GERD: 530.81, Esophageal reflux (ICD-10: K21.9, Gastro-esophageal reflux disease without esophagitis).

Tip: ICD-10 includes a category for subsequent acute myocardial infarction, I22.- (Subsequent ST elevation [STEMI] and non-ST elevation [NSTEM]) myocardial infarction). These codes apply when a patient who had an AMI has another one within 28 days and are used alongside I21.- AMI codes.